Lithography nanowires

A break junction can also be created by passing a current (0.5-1.0 V) through an Au nanowire (<20 nm diameter) defined by electron-beam lithography and shadow evaporation. Such electromigrated break junctions (EMBJs) have yielded reproducible 1-3 nm gaps between electrodes [48-50]. 

Fig. 8. Schematic of the procedure used for fabrication of nanoscale molecular-switch devices by imprint lithography [62]. (a) Deposition of a molecular film on Ti/Pt nanowires and their micron-scale connections to contact pads, (b) Blanket evaporation of a 7.5 nm Ti protective layer, (c) Imprinting of 10 nm Pt layers with a mold that was oriented perpendicular to the bottom electrodes and aligned to ensure that the top and bottom nanowires crossed, (d) Reactive ion etching with CF4 and O2 (4 1) to remove the blanket Ti protective layer.

Figure 9 Examples of novel materials with potential catalytic applications. From left to right and top to bottom, these pictures represent (a) Ag nanowires. (Reprinted with permission from Ref 63. 2002 American Chemical Society) (h)Ag nanoparticles. (Reprinted with permission from Y. Sim and Y. Xia, Science, 2002, 298, 2176. 2002 AAAS (www.sciencemag.org)) (c) zeolite monolith. (Ref. 67. Reproduced hy permission of Kluwer Academic/Plenum Publishers) (d) zeolite coatings on stainless steel grids. (Ref 68. Reproducedby permission of Wiley-VCH) (e) arrays of Pt nano lithography-made particles on Si02. (Ref. 70. Reproduced by permission of Kluwer Academic/Plenum Publishers) and (f) Ag nanoparticles vapor deposited on an AI2O3 thin film ...

Hanrath, T. Korgel, B.A. Germanium nanowire transistors a comparison of electrical contacts patterned by electron beam lithography and beam-assisted chemical vapor deposition. J. Nanoeng. Nanosyst. 2005, 218, 25-34. 

L. Francioso, P. Siciliano, Top-down contact lithography fabrication of a Ti02 nanowire array over a Si02 mesa . Nanotechnology, 17, 3761-3767, (2006). 

One-dimensional (1-D) nanosbuctures (b) are composed mainly of nanowires, nanorods and nanobelts. Spontaneous growth, template-based synthesis and electrospinning are considered bottom-up approaches, while lithography is a top-down technique [7, 84]. Two-dimensional (2-D) nanostructures (c) involve thin films, which have been the object of intensive study for almost a century and for which many methods have been developed and improved. 

For single-nanowire devices, highly expensive techniques (such as a focused ion beam, or a series of nano-lithographic tools) must be used, ranging from proton and electron beam nanoUthography, in which patterned substrates are obtained under the application of a charged particle beam, to nano-imprint lithography. ... 

Mdrtensson T, Carlberg P, Borgstrom M, Montelius L, Seifert W, Samuelson L. Nanowire arrays defined by nanoimprinting lithography. Nano. Lett. 2004 4 699-702. 

Soft lithography includes a collection of lithographic methods in which a soft mold or template is used to create patterned structures in the subjeeted materials. These methods offer attractive solutions for producing well-ordered CP nanowires. For example, Beh et al have developed a micromolding in capillaries (MIMIC) process in which a poly(dimethylsiloxane) (PDMS) mold with embedded ehannels can be used for the... 

Figure 10.5 SFM images of narrow nanowires (278 nm) of semiconducting polymer poly(3-(2 -methoxy-5 -octyphenyhthiophene) (POMeOPT) by soft-embossing. (Reprinted with permission from Nano Letters, Conducting Polymer Nanowires and Nanodots made with Soft Lithography by Fengling Zhang et al., 2, 12. Copyright (2002) American Chemical Society)...

Figure 10.6 Procedure for polymer nanowire fabrication. An aqueous PEDOTtPSS solution was spin-coated on a substrate patterned with a 1.3 ym period grating, then coated with a thin Si02 layer and a PDMS homopolymer brush. A PS-PDMS block-copolymer thin film was then spin-coated and solvent-annealed. The self-assembled block-copolymer patterns were transferred into the underlying PEDOT-.PSS film through a series of reactive ion etching steps employing CF4 and O2 plasmas. (Reprinted with permission from Nano Letters, Nanowire Conductive Polymer Gas Sensor Patterned Using Self-Assembled Block Copolymer Lithography by Y. S. Jung et al., 8, 11. Copyright (2008) American Chemical Society)...

Figure 10.16 A general concept for the production of nanowires an AFM is used as a nanomechanical tool for scratching a resist layer, to result in selective exposure of the underlying polymeric dopant surface containing the catalyst for polymerization. Treatment with the pyrrole monomer results in polymerization in the nanochannels. (Reprinted with permission from ChemPhysChem, In Situ Polymerisation of Pyrrole in Nanochannels Produced by Means of AFM Lithography by S. Jahromi, ). Dijkstra, E. van der Vegte and B. Mostert, 3, 8, 693-696. Copyright (2002) Wiley-VCH)...

D.J. Lipomi, R.C. Chiechi, M.D. Dickey, and G.M. Whitesides, Fabrication of conjugated pol3mier nanowires by edge lithography. Nano Lett., 8, 2100-2105 (2008). 

Y.S. Jung, W. Jung, H.L. Fuller, and C.A. Ross, Nanowire conductive polymer gas sensor patterned using self-assembled block copol3mier lithography. Nano Lett., 8, 3776-3780 (2008). 

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